Resilient supporting device for operator cabin

ABSTRACT

A shock absorbing device provided with a damping plate damper having a viscosity damper includes: a case body comprising an upper flange, a body portion, and a lower flange; a collared resilient member provided with a body portion and a collar portion, an outer surface of the body portion and an undersurface of the collar portion being connected to the case body; a center shaft connected to the central portion of the collared resilient member; a damping plate fixed to the bottom end portion of the center shaft; and a damper case fixed to the bottom end of the case body and filled with a viscous substance. An operator cabin of a construction machine is resiliently supported to the vehicle body through the shock absorbing device. For this reason, the number of natural vibration of the operator cabin during high speed running of a hydraulic power shovel is increased, whereby resonance thereof with the gear engaging frequencies of a caterpillar track and a sprocket wheel is avoided, so that effective damping effects can be achieved against the number of excited vibrations applied in wide ranges by the construction machines and the like, thus improving riding comfort for an operator and the mechanical strength of the operator cabin.

TECHNICAL FIELD

The invention relates to an operator cabin mounted on a constructionmachine, such as a hydraulic power shovel, and more particularly, to aresilient supporting device for resiliently supporting an operator cabinon a vehicle body.

BACKGROUND ART

FIG. 9 is a side view showing the appearance of a typical hydraulicpower shovel applied to general use, including an operator cabin 1, anupper turning body 2, an upper turning body frame 2a, and a lowertraveling body 3.

FIG. 10 is a longitudinal section showing the relation of placementbetween the operator cabin 1 and the upper turning body frame 2a, inwhich a floor plate 21a of the operator cabin 1 is mounted by a shockabsorbing device 24 to a supporting frame 22b to which the upper turningbody frame 2a is welded.

FIG. 12 is a longitudinal section showing the detail of the relatedconnection between the floor plate 21a, the supporting frame 22b, andthe shock absorbing device 24. In FIG. 12, a resilient member 24a, whichfills up a case 24c, arranged between the floor plate 21a and thesupporting frame 22b, and a resilient member 24b, which fills up a case24d, sandwich the supporting frame 22b therebetween. A floor boss 21bwelded on the floor plate 21a penetrates the case 24c, the resilientmember 24a, the case 24d, and the resilient member 24b, and a bolt 26 isfastened to the floor boss 21b, so that a predetermined distance isprovided between the resilient members 24a and 24b for tightening thefloor plate 21a and the supporting frame 22b during assembly. Also, abracket 21c, which is welded on the frame of the operator cabin 1, isfastened to the floor plate 21a by a bolt 27.

In this manner, as shown in FIG. 11, four shock absorbing devices 24 areplaced in both corners of the front and back ends of the operatorcabin 1. Resilient members 25 are placed between the periphery of thefloor boss 21b and the periphery of the holes in the supporting frames22b through which the floor boss 21b extends, so that the horizontalsurface of the operator cabin 1 can be resiliently located against theupper turning body frame 2a. However, in the prior art mentioned above,since the floor plate 21a of the operator cabin 1 is connected to thesupporting frame 22b of the upper turning body 2 by the four shockabsorbing devices 24, the number of natural vibrations of the operatorcabin 1 becomes small, whereby the number of natural vibrations of theoperator cabin 1 during high speed running of a hydraulic power shovelbecomes close to the gear engaging frequencies provided by a caterpillartrack and a sprocket wheel, so that the operator cabin 1 resonatestherewith. For this reason, the vibration of the operator cabin 1 isincreased, especially the rolling from side to side is increased. Whilethe main object of the above-mentioned prior art is to provide shockabsorbing effects by the shock absorbing devices 24, damping effectsagainst increased vibrations produced by resonance of the operator cabin1 are not effective, thus deteriorating the riding comfort for anoperator during high speed running as well as the mechanical strength ofthe operator cabin 1.

Therefore, an object of the present invention is to solve theabove-mentioned problems and provide the resilient supportingconstruction of the operator cabin 1 against the vehicle body to reducevibrations, particularly during high speed running of the hydraulicpower shovel, and prevent trailing turns of resilient members duringassembly of the shock absorbing devices 24.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a longitudinal section of a first embodiment according to thepresent invention, showing an overview of related placement of a shockabsorbing device, having a damping plate damper 4, to an upper turningbody frame 2a and an operator cabin 1.

FIG. 2 is a detailed longitudinal section of a shock absorbing devicehaving a damping plate damper 4 of FIG. 1, showing related connectionbetween a floor plate 1a of the operator cabin 1 and a supporting frame2b of the upper turning body frame 2a.

FIG. 3 is a comparison graph showing vibration transfer characteristicsof an operator cabin shock absorbing device with a damping plate damperaccording to each embodiment of the present invention or with a rubbermount according to the prior art.

FIG. 4 is a comparison graph showing loss factors of an operator cabinshock absorbing device with a damping plate damper according to eachembodiment of the present invention or with a rubber mount according tothe prior art.

FIG. 5 is a longitudinal section, similar to FIG. 2, showing a shockabsorbing device with a damping plate damper according to a secondembodiment of the present invention.

FIG. 6 is a cross-sectional view, taken on line A--A of FIG. 5.

FIG. 7 is a longitudinal section, similar to FIG. 2, showing a shockabsorbing device with a damping plate damper according to a thirdembodiment of the present invention.

FIG. 8 is a cross-sectional view, taken on line B--B of FIG. 7.

FIG. 9 is a side view showing the appearance of a typical hydraulicpower shovel.

FIG. 10 is a longitudinal section showing the relation of placementbetween an operator cabin 1 and an upper turning body frame 2a shown inFIG. 9 according to the prior art.

FIG. 11 is a plan view showing the locations of the shock absorbingdevices 24 illustrated in FIG. 10.

FIG. 12 is a detailed longitudinal section showing the vicinity of ashock absorbing device 24 illustrated in FIG. 10.

SUMMARY OF THE INVENTION

The first aspect of the present invention is to provide a resilientsupporting device for resiliently supporting an operator cabin on avehicle body of a construction machine, the resilient supporting devicecomprising a shock absorbing device with a damping plate damper, so thatremarkable shock absorbing and damping effects can be achieved against anumber of excited vibrations applied in wide ranges by the constructionmachine.

The second aspect of the present invention is to provide a shockabsorbing device, with a damping plate damper having a viscosity damperaccording to the first aspect of the present invention, including: acase body having an upper flange, a body portion, and a lower flange; acollared resilient member provided with a body portion and a collarportion, an outer surface of the body portion and an undersurface of thecollar portion being connected to the case body; a center shaftconnected to the central portion of the collared resilient member; adamping plate fixed to the bottom end portion of the center shaft; and adamper case fixed to the bottom end of the case body and filled with aviscous substance; whereby the operator cabin is secured to the upperportion of the center shaft and is supported on the upper surface of thecollar portion of the collared resilient member. For this reason,effective shock absorbing and damping effects in the upper and lowerside directions can be achieved against a number of excited vibrationsapplied in wide ranges by the construction machines and the like.Moreover, the collar portion and the body portion of the collaredresilient member resiliently resist any inclination to the vertical bythe center shaft, the upper portion of which is secured to the operatorcabin, whereby rolling vibrations in every side direction can becertainly reduced.

The third aspect of the present invention is to provide a shockabsorbing device, with a damping plate damper having a viscosity damperaccording to the second aspect of the present invention, wherein anupper resilient stopper is connected to the case body for controllinglower movement of the operator cabin and which is spaced a predetermineddistance from the periphery of the collar portion of the collaredresilient member, and wherein a lower resilient stopper for controllingupper movement of the operator cabin is connected to the lower surfaceof the damping plate. Therefore, after moving downwardly and strikingthe upper resilient stopper, the operator cabin moves downwardly in astate of increasing spring constant; after moving upwardly and strikingthe lower resilient stopper, the operator cabin moves upwardly in astate of increasing spring constant; whereby remarkable shock absorbingeffects can be achieved in upper and lower movement of the operatorcabin. Thus, according to the first to third aspects of the presentinvention, remarkable effects can be obtained as follows:

(1) Since effective shock absorbing and damping effects are achievedagainst a number of excited vibrations applied in wide ranges by theconstruction machines and the like, riding comfort for an operator andthe durability of the operator cabin can be improved without even one ofdevices being adjusted in response to the number of excited vibrationsin wide ranges.

(2) Without even one of devices being adjusted in response to the numberof excited vibrations applied in wide ranges by the constructionmachines and the like, effective shock absorbing and damping effects inthe upper and lower side directions are achieved. Moreover, rollingvibrations in every side direction, which is a big problem in the priorart, can be certainly reduced so that riding comfort for an operator andthe durability of the operator cabin can be remarkably improved.

(3) After striking each resilient stopper, in a state of increasingspring constant, upper and lower movement of the operator cabin iscontrolled, whereby effective shock absorbing effects can be achievedfor the operator cabin, thus improving riding comfort for an operatorand the durability of the operator cabin.

The fourth aspect of the present invention is to provide a shockabsorbing device with a damping plate damper having a viscosity damper,including: a case body comprising an lower flange, a body portion, and alower flange; a collared resilient member provided with a body portionand a collar portion, an outer surface of the body portion and anundersurface of the collar portion being connected to the case body; acenter shaft connected to the central portion of the collared resilientmember; a damping plate fixed to the bottom end portion of the centershaft; and a damper case fixed to the bottom end of the case body andfilled with a viscous substance; whereby the collar portion of thecollared resilient member and the operator cabin are fixed to each otherthrough a spacer by the center shaft, and the lower flange of the casebody is fixed to the vehicle body; and the improvement wherein thespacer and the center shaft have mating flats, and a turning preventiondevice is provided adjacent to the center shaft and the spacer forpreventing twisting of the center shaft.

The fifth aspect of the present invention is to provide a shockabsorbing device with a damping plate damper having a viscosity damperincluding: a case body comprising an lower flange, a body portion, and aupper flange; a collared resilient member provided with a body portionand a collar portion, an outer surface of the body portion and anundersurface of the collar portion being connected to theabove-described case body; a center shaft connected to the centralportion of the collared resilient member; a damping plate fixed to thebottom end portion of the center shaft; and a damper case fixed to thebottom end of the case body and filled with a viscous substance; wherebythe collar portion of the collared resilient member and the operatorcabin are fixed to each other through a spacer by the center shaft, andthe lower flange of the case body is fixed to the vehicle body; and theimprovement wherein a lockpin is provided to engage the center shaft andthe spacer, and a turning prevention device is provided adjacent to thecenter shaft and the spacer for preventing twisting of the center shaft.Therefore, according to the fourth and fifth aspects of the presentinvention, trailing turns are prevented during tightening by an impactwrench, whereby the twisting of the resilient member can be avoided,thus enabling certain fastening by the impact wrench and preventinginconveniences provided by flexure. Furthermore, such a mechanism canimprove the durability of the rubber mount and facilitate the placementof the turning prevention device adjacent to the center shaft and thespacer.

BEST MODE FOR CARRYING OUT THE INVENTION

In FIG. 1, showing a first embodiment of the present invention, thereare provided a floor plate 1a engaged by a bolt 1f with a bracket 1cwelded to an operator cabin 1, a supporting frame 2b welded to an lowerturning body frame 2a, and a shock absorbing device provided with adamping plate damper 4 for resiliently supporting the floor plate 1a ofthe operator cabin 1 to the supporting frame 2b to which the lowerturning body frame 2a is welded.

In FIG. 2, the shock absorbing device provided with a damping platedamper 4 includes a case body comprising an lower flange 4a, a upperflange 4b, and a body portion 4c; a collared resilient member comprisinga resilient member collar portion 4e, a resilient member body portion4f, and an upper resilient stopper portion 4g; a center shaft 4hpenetrating a central portion of the resilient member collar portion 4eand of the resilient member body portion 4f; a damping plate 6 securedby a bolt 5 to a upper end of the center shaft 4h; a lower resilientstopper 6a connected to the periphery of an upper surface of the dampingplate 6; holes 6b provided in the damping plate 6; and a viscositydamper comprising a damper case 4d attached to the lowers flange 4b andfilled with silicon oil.

An undersurface of the resilient member collar portion 4e contacts anuppersurface of the upperflange 4a of the case body, an outer surface ofthe resilient member body portion 4fcontacts an internal surface of thebody portion 4c of the case body, and the periphery surface of thecenter shaft 4h contacts the inner periphery surface of the resilientmember collar portion 4e and of the resilient member body portion 4f.The vibration transmissibility T of the viscosity damper is determinedin response to the number and the size of the holes 6b provided in thedamping plate 6. The resilient member collar portion 4e and the operatorcabin 1 are fixed to each other through the spacer 8 by a nut 10 and alock washer 9 engaging an upper threaded portion 4i of the center shaft4h. The upper flange 4a of the case body is fixed to the supportingframe 2b of the vehicle body by a bolt 11 and a nut 12. Also, the upperresilient stopper 4g is positioned outwardly from the periphery of theresilient member collar portion 4e with an upper surface of the upperresilient stopper 4gbeing spaced from an undersurface of the floor plate1a of the operator cabin 1 by a predetermined distance.

Next, the operation of the first embodiment of the present invention asshown in FIGS. 1 and 2 will be described. The weight of the operatorcabin 1, in a state where the floor plate 1a of the operator cabin 1rests on the upper surface of the resilient member collar portion 4e, issupported by the compressive force of the resilient member collarportion 4e and the shearing force of the resilient member body portion4f. The center shaft 4h fixed to the floor plate 1a of the operatorcabin 1 is supported by the resilient member collar portion 4e throughthe lowers flange 4a of the case body and the supporting frame 2b, whichis fixed to the vehicle body, thus resiliently supporting the operatorcabin 1 to the vehicle body. Therefore, the resilient member collarportion 4e and the resilient member body portion 4fresiliently resistany inclination from the vertical by the center shaft 4h, with theoperator cabin 1 being fixed to the upper portion of the center shaft4h, whereby rolling vibrations in every side direction can be certainlyreduced. Also, by the viscosity damper having the damping plate 6 fixedto the lowers end of the center shaft 4h, and by the damper case 4dwhich contains the damping plate 6 being filled with silicon oil 7, thevibration transmissibility T of the shock absorbing device provided witha damping plate damper 4 as shown in FIG. 3 is determined in response tothe number and the size of the holes 6b provided on the damping plate 6.In the construction according to the first embodiment, not onlyremarkable damping effects are achieved against the number of excitedvibrations, which are changed by the conditions of running and operationapplied in wide ranges by the construction machines and the like, butalso upper and lower movement of the operator cabin 1 can be controlledby each resilient stopper 4g or 6a, whereby the floor plate 1a strikesthe upper resilient stopper 4g or the lower stopper 6a strikes the lowerflange 4b. In such a state of an increasing spring constant, upper andlower movement of the operator cabin is controlled, so that effectiveshock absorbing effects can be achieved for the operator cabin 1.

FIG. 3 is a comparison graph showing vibration transfer characteristicsT of the shock absorbing device with a damping plate damper 4 accordingto each embodiment of the present invention or with a rubber mountaccording to the prior art, giving the excited frequency f (Hz) on theaxis of abscissa and the vibration transmissibility T on the axis ofordinate. In FIG. 3, according to the prior art, shown with a brokenline, the vibration transmissibility T is approximately 2.3 at anexcited frequency f of approximately 11 Hz, while the vibrationtransmissibility T according to each embodiment of the present inventionis approximately 1.2, i.e., thus, the vibration transmissibility T isreduced by almost half for the present invention.

FIG. 4 is a comparison graph showing loss factors of the shock absorbingdevice with a damping plate damper 4 according to each embodiment of thepresent invention or with a rubber mount according to the prior art,giving the excited frequency f (Hz) on the axis of abscissa and the lossfactor (tan δ) on the axis of ordinate. In FIG. 4, for the constructionwherein the operator cabin 1 is placed on the rubber mounts of the priorart, the loss factors (tan δ), shown with a broken line, in a range ofthe excited frequencies f up to 30 Hz are within a range ofapproximately 0.2 to 0.25, while the loss factors (tan δ) in a range ofthe excited frequencies f up to 30 Hz are set in a range ofapproximately 0.2 to 0.25, while the loss factors according to eachembodiment of the present invention are larger, approximately 0.8 or so,i.e., the damping effects according to the present invention are largerthan the prior art.

Generally, the relation of the vibration transmissibility T and the lossfactor (tan δ) is shown in the following equation.

    T=√ 1+tan.sup.2 δ/√ (1-f/fn).sup.2 +tan.sup.2 δ(1)

wherein, f= excited frequency, fn= natural frequency.

As shown in FIG. 2, when the resilient member collar portion 4e and thefloor plate 1a of the operator cabin 1 are fixed to each other throughthe spacer 8 by the use of a box spanner 13 to effect the engagement ofthe nut 10 and the lock washer 9 with the upper threaded portion 4i ofthe center shaft 4h by an application of a torque in the direction ofthe arrow, the rotation force on the center shaft 4h transmits a twistto the resilient member collar portion 4e and the resilient member bodyportion 4f, whereby it may be difficult to completely fasten.Furthermore, since the resilient member collar portion 4e and theresilient member body portion 4f are assembled in a twisted state, therearises another problem in that the durability of the resilient membercollar portion 4e and the resilient member body portion 4f isdeteriorated. Therefore, a lockpin can be placed between the centershaft 4h and the floor plate 1a of the operator cabin 1 in order to stopturning of the center shaft 4h. When it is necessary to mount aplurality of the shock absorbing devices provided with the damping platedamper 4, problems arise in that close dimensional tolerances oflockpins are required and the number of processes is increased.

FIGS. 5 and 6 are sectional views showing a construction for stoppingrotation of the center shaft 4h in order to prevent twisting of theresilient member collar portion 4e and the resilient member body portion4f according to the second embodiment of the present invention.Hereinafter, referring to FIGS. 5 and 6, the second embodiment of thepresent invention will be described. Since the relation of the placementof the shock absorbing device provided with the damping plate damper 4to the upper turning body frame 2a and the operator cabin 1 is the sameas that shown in FIG. 1, a detailed description thereof will be omitted.Also, for the construction which corresponds to that of the firstembodiment of the present invention shown in FIG. 2, a detaileddescription of the construction and operation thereof will be omitted.

As shown in the drawings, the resilient member collar portion 4e isfastened through a spacer 14 to the floor plate 1a of the operator cabin1 by the nut 10 engaging a threaded portion 4i of the center shaft 4h,and the upper flange 4a of the case body is fixed to the vehicle body,so that a resilient supporting device of the operator cabin 1 isprovided. In the upper portion of the center shaft 4h, two verticalflats 4j--4j are formed which engage corresponding vertical flats14a--14a formed on the spacer 14. A pin bolt 15 is engaged with a tappedhole 1d provided in the floor plate 1a of the operator cabin 1, wherebythe pin portion of the bolt 15 extends through a pin hole 14c formed ina radial projection 14b of the spacer 14, thus preventing rotation ofthe center shaft 4h. Further, the upper flange portion 4a of the casebody is fixed to the supporting frame 2b by the bolt 11 and the nut 12,and the upper surface of the upper resilient stopper 4g is positioned apredetermined distance from the undersurface of the spacer 14. Inaddition, since the relation of placement of the shock absorbing deviceprovided with the damping plate damper 4 to the upper turning body frame2a and the operator cabin 1 is the same as that shown in FIG. 1, adescription thereof will be omitted.

Next, the operation of the second embodiment will be described. When theshock absorbing device provided with the damping plate damper 4 attachedto the supporting frame 2b of the upper turning body 2a is fixed to thefloor plate 1a of the operator cabin 1, the flats 4j--4j of the centershaft 4h fit in a slot in the spacer 14 having the corresponding flats14j--14j. A threaded portion 4i of the tip of the center shaft 4h islocated relative to a hole 1e in the floor plate 1a, and then theoperator cabin 1 is moved downwardly until the upper surface of thespacer 14 contacts the undersurface of the floor plate 1a.

Also, when the pin bolt 15 is engaged from above with the threadedportion 1d of the floor plate 1a, the pin portion of the pin bolt 15extends into the pin hole 14c of the spacer 14. Thereafter, although thefloor plate 1a is fastened to the shock absorbing device by the nut 10and the lock washer 9 engaging the threaded portion 4i of the centershaft 4h, the flats 14a--14a and 4j--4j and the pin bolt 15 prevent theturning of the center shaft 4h, whereby twisting of the resilient membercollar portion 4e and the resilient member body portion 4f, as producedin the conventional devices, can be avoided.

FIGS. 7 and 8 are sectional views showing the construction for stoppingrotation of a center shaft 4m in order to prevent twisting of theresilient member collar portion 4e and the resilient member body portion4f according to the third embodiment of the present invention.Hereinafter, referring to FIGS. 7 and 8, the third embodiment of thepresent invention will be described. In addition, since the relation ofplacement of the shock absorbing device provided with the damping platedamper 4 to the upper turning body frame 2a and the operator cabin 1 isthe same as that shown in FIG. 1, a detailed description thereof will beomitted. Also, for the construction which corresponds to the firstembodiment of the present invention shown in FIG. 2, a detaileddescription of the construction and operation thereof will be omitted.

An upper surface of a collar portion 4k of a collared resilient memberis different from that of the second embodiment as the upper surfacethereof does not strike the floor plate 1a of the operator cabin 1,whereby the operator cabin 1 is supported by shearing force of theresilient member collar portion 4k and the resilient member body portion4f. The center shaft 4m and the floor plate 1a of the operator cabin 1are fastened to each other through a spacer 16 by the nut 10 and thelock washer 9 engaging the threaded portion 4i of the center shaft 4m,and the lower flange 4a of the case body is fixed to the supportingframe 2b of the upper turning body 2a by the bolt 11 and the nut 12, sothat a resilient supporting device of the operator cabin 1 is provided.

The pin bolt 15 engages the tapped hole 1d formed in the floor plate 1aof the operator cabin 1, and the pin portion of the pin bolt 15 extendsinto a pin hole 16c formed in a radial projection 16b of the spacer 16.Rotation of the spacer 16 around the center shaft 4m is prevented by alockpin 17. Also, the upper flange portion 4a of the case body is fixedto the supporting frame 2b by the bolt 11 and the nut 12.

Next, the operation of the third embodiment will be described. When theshock absorbing device provided with the damping plate damper 4 attachedto the supporting frame 2b of the upper turning body 2a is fixed to thefloor plate 1a of the operator cabin 1, a bolt hole in the spacer 16 islocated relative to a threaded portion 4i of the center shaft 4m and thelockpin 17 is placed in a pin hole in the spacer 16 and in a pin hole inthe center shaft 4m, whereby the spacer 16 and the center shaft 4m areassembled.

Next, the threaded portion 4i of the tip of the center shaft 4m islocated relative to the hole 1e in the floor plate 1a, and then theoperator cabin 1 is moved downwardly until the undersurface of the floorplate 1a contacts the upper surface of the spacer 16. Thereafter, thepin bolt 15 is inserted from above into the bolt hole 1d of the floorplate 1a, with the pin portion of the pin bolt 15 extending into the pinhole 16c of the spacer 16, and the floor plate 1a is fastened to thecenter shaft 4m and the spacer 16 by using a wrench to cause the nut 10and the lock washer 9 to engage with the threaded portion 4i of thecenter shaft 4m, so that the rotation of the center shaft 4m isprevented, whereby twisting of the resilient member collar portion 4kand the resilient member body portion 4f, as produced in theconventional devices, can be avoided.

INDUSTRIAL APPLICABILITY

The present invention is to provide an effective resilient supportingdevice for resiliently supporting an operator cabin against a vehiclebody of a construction machine, such as a hydraulic power shovel, sothat the riding comfort for an operator and the mechanical strength ofthe operator cabin can be improved.

What is claimed is:
 1. A machine having a vehicle body, an operatorcabin, and a resilient supporting device for resiliently supporting saidoperator cabin on said vehicle body, said resilient supporting devicecomprising a shock absorbing device having a damping plate damper,wherein said shock absorbing device having a damping plate dampercomprises:a case; a center shaft positioned within said case and havinga length within said case; a resilient member positioned between andconnected to said center shaft along substantially the length thereofwithin said case and to said case and defining with said case a chamberin a lower portion of said case, said chamber containing a viscoussubstance; and a damping plate fixed to a bottom end portion of saidcenter shaft and positioned within said viscous substance; said operatorcabin being secured to an upper end portion of said center shaft.
 2. Amachine having a vehicle body, an operator cabin, and a resilientsupporting device for resiliently supporting said operator cabin on saidvehicle body, said resilient supporting device comprising a shockabsorbing device having a damping plate damper, wherein said shockabsorbing device having a damping plate damper comprises:a case bodycomprising an upper flange, a body part, and a lower flange; said casebody having a top end and a bottom end; a collared resilient memberhaving a body portion and a collar portion; said collar portion of saidcollared resilient member having an upper surface and an undersurface;said body portion of said collared resilient member having an innersurface and an outer surface; said outer surface of the body portion ofsaid collared resilient member and said undersurface of the collarportion of said collared resilient member being connected to said casebody; a center shaft having an upper end portion, a central portion, anda bottom end portion; said central portion of said center shaft beingconnected to said inner surface of said body portion of said collaredresilient member; a damper case secured to said bottom end of said casebody and containing a viscous substance; and a damping plate fixed tosaid bottom end portion of said center shaft and positioned within saidviscous substance; said operator cabin being secured to said upper endportion of said center shaft.
 3. A machine in accordance with claim 2,further comprising a connector for connecting said upper flange of saidcase body to said vehicle body.
 4. A machine in accordance with claim 2,wherein said outer surface of the body portion of said collaredresilient member is connected to an inner surface of said body part ofsaid case body, and wherein said undersurface of the collar portion ofsaid collared resilient member is connected to an upper surface of saidupper flange of said case body.
 5. A machine in accordance with claim 2,wherein said central portion of said center shaft is connected to saidinner surface of said body portion of said collared resilient member andto an inner surface of said collar portion of said collared resilientmember.
 6. A machine in accordance with claim 2, wherein said operatorcabin comprises a floor plate having an opening therethrough, whereinsaid upper end portion of said center shaft comprises a threaded portionwhich extends through said opening in said floor plate of said operatorcabin, and wherein a nut is provided in engagement with said threadedportion of said center shaft so as to secure said center shaft to saidoperator cabin, whereby said operator cabin is supported on said uppersurface of said collar portion of said collared resilient member.
 7. Amachine in accordance with claim 2, further comprising a spacerpositioned between said operator cabin and said collared resilientmember, said spacer having an opening therethrough, wherein said centershaft extends through said opening in said spacer.
 8. A machine inaccordance with claim 7, wherein the opening in said spacer is providedwith flats, and wherein said center shaft is provided with flats whichengage the flats of said spacer to prevent rotation of said center shaftwith respect to said spacer.
 9. A machine in accordance with claim 8,further comprising a pin hole in said operator cabin and a mating pinhole in said spacer, and a pin extending through said pin hole in saidoperator cabin and said pin hole in said spacer to prevent rotation ofsaid spacer with respect to said operator cabin.
 10. A machine inaccordance with claim 7, further comprising a hole in said spacer and amating hole in said center shaft, and a lockpin extending through saidhole in said spacer and said hole in said center shaft to preventrotation of said spacer with respect to said center shaft.
 11. A machinein accordance with claim 10, further comprising a pin hole in saidoperator cabin and a mating pin hole in said spacer, and a pin extendingthrough said pin hole in said operator cabin and said pin hole in saidspacer to prevent rotation of said spacer with respect to said operatorcabin.
 12. A machine in accordance with claim 2, further comprising anupper resilient stopper connected to said case body for controllinglower movement of said operator cabin, said upper resilient stopperbeing spaced outwardly from the periphery of the collar portion of saidcollared resilient member; and a lower resilient stopper for controllingupper movement of said operator cabin, said lower resilient stopperbeing connected to an upper surface of said damping plate.
 13. A machinein accordance with claim 12, further comprising a spacer positionedbetween said operator cabin and said collared resilient member, saidspacer having an opening therethrough, wherein said center shaft extendsthrough said opening in said spacer, and wherein said upper resilientstopper is spaced a predetermined distance from said operator cabin. 14.A machine in accordance with claim 13, wherein the opening in saidspacer is provided with flats, and wherein said center shaft is providedwith flats which engage the flats of said spacer to prevent rotation ofsaid center shaft with respect to said spacer.
 15. A machine inaccordance with claim 14, further comprising a pin hole in said operatorcabin and a mating pin hole in said spacer, and a pin extending throughsaid pin hole in said operator cabin and said pin hole in said spacer toprevent rotation of said spacer with respect to said operator cabin. 16.A machine in accordance with claim 13, further comprising a hole in saidspacer and a mating hole in said center shaft, and a lockpin extendingthrough said hole in said spacer and said hole in said center shaft toprevent rotation of said spacer with respect to said center shaft.
 17. Amachine in accordance with claim 16, further comprising a pin hole insaid operator cabin and a mating pin hole in said spacer, and a pinextending through said pin hole in said operator cabin and said pin holein said spacer to prevent rotation of said spacer with respect to saidoperator cabin.
 18. A machine in accordance with claim 17, wherein saidouter surface of the body portion of said collared resilient member isconnected to an inner surface of said body part of said case body, andwherein said undersurface of the collar portion of said collaredresilient member is connected to an upper surface of said upper flangeof said case body.
 19. A machine in accordance with claim 2, furthercomprising a connector for connecting said upper flange of said casebody to said vehicle body; wherein said outer surface of the bodyportion of said collared resilient member is connected to an innersurface of said body part of said case body, and wherein saidundersurface of the collar portion of said collared resilient member isconnected to an upper surface of said upper flange of said case body.20. A machine in accordance with claim 19, wherein said central portionof said center shaft is connected to said inner surface of said bodyportion of said collared resilient member and to an inner surface ofsaid collar portion of said collared resilient member, wherein saidoperator cabin comprises a floor plate having an opening therethrough,wherein said upper end portion of said center shaft comprises a threadedportion which extends through said opening in said floor plate of saidoperator cabin, and wherein a nut is provided in engagement with saidthreaded portion of said center shaft so as to secure said center shaftto said operator cabin.